A small and wide angle electron diffraction apparatus and method

Abstract

The application discloses a kind of small angle and wide angle electron diffraction device and method, solve the insufficient resolution capability of the existing electron diffraction device to the small angle diffraction and diffuse scattering signal near transmission electron beam axis, it is difficult to obtain wide angle diffraction and small angle diffraction information under the same time delay condition, the first detection component and the second detection component are arranged in the same device in the present application, the whole wide angle diffraction region and the small angle diffraction region near transmission electron beam can be detected respectively;Therefore, the interference of strong transmission electron beam to weak small angle diffraction signal and central region diffuse scattering signal can be effectively avoided, the resolution capability and utilization efficiency of small angle diffraction signal are improved, and it is beneficial to obtain long period structure, mesoscopic scale order or disorder characteristics and interface distribution and other structure information.

Description

Technical Field

[0001] This invention relates to electron diffraction apparatus and methods, and more specifically to a small-angle and wide-angle electron diffraction apparatus and method. Background Technology

[0002] Electron diffraction is a spatiotemporally resolved technique that uses ultrashort pulsed electron beams to detect the nonequilibrium structural evolution of matter. It can capture lattice reconstruction, phase transitions, and collective excitation processes on femtosecond to picosecond timescales and is widely used in the study of nonequilibrium structural dynamics in superconductors, phase transition materials, layered quantum materials, and low-dimensional materials. Typical electron diffraction devices use DC or radio frequency electron guns to generate ultrashort pulsed electron beams, which are then focused and trajectory-controlled by an electron optics system before being incident on the sample. A fluorescent screen or electron detector is usually placed behind the sample at a predetermined camera length to record electron diffraction patterns at different time delays, thereby obtaining time-resolved information on the material's structural evolution.

[0003] However, existing electron diffraction devices still have significant shortcomings in acquiring dynamic information about complex structures.

[0004] First, existing devices lack the ability to resolve and utilize small-angle diffraction (SAD) and diffuse scattering signals in the central region near the transmitted electron beam. SAD signals correspond to relatively small scattering vectors and are highly sensitive to information such as long-period structures, mesoscale ordered or disordered features, and interface distributions. However, in traditional single-detector structures, the strong SOD is typically located in the central region of the diffraction pattern, easily causing saturation of the fluorescent screen or detector center, thus obscuring the weaker SAD and diffuse scattering signals near the SOD. Furthermore, traditional devices typically lack a dedicated amplified detection optical path for the SAD region, making it difficult to perform accurate analysis of this region with high signal-to-noise ratio and high resolution. Therefore, while existing devices can record conventional wide-angle diffraction patterns, their ability to extract SAD information is insufficient.

[0005] Secondly, existing devices struggle to simultaneously acquire wide-angle and small-angle diffraction information under the same time delay. Traditional electron diffraction devices typically use a single fluorescent screen or detector to record the overall diffraction pattern, and the pattern unfolding scale on the detector surface is primarily influenced by the camera length between the sample and the detector. Wide-angle diffraction usually requires a large detection field of view, while small-angle diffraction necessitates local magnification of the region near the transmitted electron beam to resolve weak small-angle diffraction signals and diffuse scattering signals. Due to the different requirements for detection field of view and pattern magnification, traditional single-detector structures cannot simultaneously handle both large-field-of-view wide-angle diffraction detection and high-resolution small-angle diffraction detection. Experiments often require changing the camera length, altering detection conditions, or reconfiguring the detection optical path to acquire wide-angle and small-angle diffraction information separately, leading to complex experimental operations and increasing the difficulty of synchronous correlation analysis of diffraction data at different scales.

[0006] Third, existing devices lack the ability to selectively gate, extract, and perform high-magnification detection of specific diffraction regions. For material systems with localized structural distortions, defect evolution, phase separation, or specific diffraction spot responses, researchers often need to perform detailed detection of a specific diffraction spot or diffuse scattering region. However, traditional electron diffraction devices can usually only perform a one-time detection of the overall diffraction pattern, lacking a structure capable of extracting selected local diffraction electron beams from the overall diffraction electron beam group and performing magnified imaging. This makes it difficult to achieve high-magnification detection and analysis of local diffraction regions, limiting the ability to resolve details of local structural dynamics.

[0007] Fourth, existing devices lack flexibility in adjusting diffraction detection magnification and detection modes. The pattern magnification of traditional electron diffraction devices mainly depends on the camera length, electron beam energy, and fixed electron optical parameters. Once the device structure and detector position are determined, the adjustable range is relatively limited. When switching between wide-angle diffraction, small-angle diffraction, and high-magnification detection in local diffraction regions, it is usually necessary to move the detector, change the distance between the sample and the detector, or make significant reconfigurations to the electron optical system. This not only increases the difficulty of experimental adjustment but also easily introduces geometric calibration errors and repeatability problems, which is not conducive to continuous, stable, and correlated detection of multi-scale diffraction information under the same experimental conditions.

[0008] In summary, existing electron diffraction devices still have shortcomings in acquiring dynamic information of complex structures. They struggle to simultaneously extract small-angle diffraction signals, simultaneously detect wide-angle and small-angle diffraction, and perform high-magnification detection of selected local diffraction regions. Furthermore, the control of diffraction detection magnification and detection modes is not flexible enough. With the increasing demand for research on long-period structures, mesoscopic ordered or disordered structures, local structural distortions, and the evolution of multi-scale non-equilibrium structures, there is an urgent need for an electron diffraction technique that can flexibly switch between and coordinately detect wide-angle diffraction, small-angle diffraction, and local diffraction details in the same device. Summary of the Invention

[0009] To address the technical problems of existing electron diffraction devices, such as insufficient resolution of small-angle diffraction and diffuse scattering signals near the axis of the transmitted electron beam, difficulty in simultaneously acquiring wide-angle and small-angle diffraction information under the same time delay, lack of ability to selectively extract and detect selected local diffraction regions at high magnification, and insufficient flexibility in adjusting diffraction detection magnification and detection mode, this invention provides a small-angle and wide-angle electron diffraction device and method.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A small-angle and wide-angle electron diffraction device is characterized by comprising an electron beam transmission channel, an electron beam generating unit arranged sequentially along the electron beam transmission channel from the incident end to the exit end, a sample chamber for placing the sample to be tested, and a first detection component and a second detection component.

[0012] The electron beam generating unit includes an electron gun vacuum chamber connected to the incident end of the electron beam transmission channel and an electron gun disposed within the electron gun vacuum chamber; the electron gun is used to emit an electron beam into the electron beam transmission channel, and the electron beam forms a scattered electron beam group after passing through the sample to be tested; the scattered electron beam group includes a transmitted electron beam and a diffracted electron beam.

[0013] The first detection component includes a first chamber connected to the electron beam transmission channel, a first fluorescent screen and a reflector sequentially arranged inside the first chamber along the emission direction of the scattered electron beam group, and a first detector arranged outside the first chamber. The first fluorescent screen has a first transmission aperture in the middle for releasing a portion of the scattered electron beam group from the first transmission aperture, which is then excited by another portion of the scattered electron beam group to form a wide-angle diffraction light signal. The reflector is arranged at an angle of 30° to 60° with the first fluorescent screen, and has a second transmission aperture in the middle corresponding to the first transmission aperture for continuing to release the portion of the scattered electron beam group from the second transmission aperture and reflecting the wide-angle diffraction light signal. The first detector is arranged in the optical path where the reflected wide-angle diffraction light signal is located to detect the wide-angle diffraction light signal and acquire a wide-angle electron diffraction image.

[0014] The second detection component includes a second chamber connected to the exit end of the electron beam transmission channel, a second fluorescent screen disposed inside the second chamber, and a second detector disposed outside the second chamber; the second fluorescent screen is capable of forming a small-angle diffraction light signal under the excitation of the partial scattered electron beam group; the second detector is used to detect the small-angle diffraction light signal to obtain a small-angle electron diffraction image.

[0015] The electron gun vacuum chamber and the sample chamber are respectively connected to vacuum pumping equipment.

[0016] Furthermore, it also includes a first pre-stage XY deflector, an electromagnetic lens, and a second pre-stage XY deflector; the first pre-stage XY deflector, the electromagnetic lens, and the second pre-stage XY deflector are sequentially arranged in the electron beam transmission channel between the electron gun vacuum chamber and the sample chamber along the electron beam emission direction; the first pre-stage XY deflector is used to deflect the electron beam emitted by the electron gun once; the electromagnetic lens is used to focus the electron beam after the first deflection; and the second pre-stage XY deflector is used to deflect the focused electron beam a second time.

[0017] Furthermore, it also includes a vacuum differential valve and an electron imaging assembly; the vacuum differential valve is disposed on the electron beam transmission channel between the first pre-stage XY deflector and the electromagnetic lens, and is used to isolate or connect the electron gun vacuum chamber and the sample chamber; the electron imaging assembly is installed on the electron beam transmission channel between the first chamber and the second chamber, and is used to magnify and image the received portion of the scattered electron beam group.

[0018] A small-angle and wide-angle electron diffraction method, employing the aforementioned small-angle and wide-angle electron diffraction apparatus, is characterized by comprising the following steps:

[0019] Step 1: Place the sample to be tested in the sample chamber.

[0020] Step 2: Evacuate the electron gun vacuum chamber and the sample chamber separately using a vacuum pump to reduce the pressure in the electron gun vacuum chamber to less than [a certain value]. The pressure inside the sample chamber is less than And maintain the differential air extraction state between the two chambers.

[0021] Step 3: An electron beam is emitted into the electron beam transmission channel through an electron gun. The electron beam enters the sample chamber and is scattered with the sample to be tested, forming a scattered electron beam group; the scattered electron beam group includes a transmitted electron beam and a diffracted electron beam.

[0022] Step 4: The first fluorescent screen allows a portion of the scattered electron beam to pass through the first transmission aperture, and under the excitation of another portion of the scattered electron beam, a wide-angle diffraction light signal is formed. The mirror continues to allow the portion of the scattered electron beam to pass through the second transmission aperture in its middle, and reflects the wide-angle diffraction light signal to the first detector. The first detector detects the reflected wide-angle diffraction light signal to obtain a wide-angle electron diffraction image of the sample under test.

[0023] Step 5: The second fluorescent screen generates a small-angle diffraction light signal under the excitation of a portion of the scattered electron beam group. The second detector detects the small-angle diffraction light signal to obtain the small-angle electron diffraction image of the sample under test, thus completing the ultra-small-angle and wide-angle electron diffraction.

[0024] Further, step 2 specifically involves closing the vacuum differential valve to isolate the electron gun vacuum chamber and the sample chamber from each other, and then using a vacuum pump to evacuate both the electron gun vacuum chamber and the sample chamber separately, so that the pressure inside the electron gun vacuum chamber is less than [a certain value]. The pressure inside the sample chamber is less than Once both chambers meet the predetermined vacuum conditions, the vacuum differential valve is opened to connect the electron gun vacuum chamber with the sample chamber, and the differential pumping state between the two chambers is maintained.

[0025] Step 3 specifically involves the electron gun emitting an electron beam into the electron beam transmission channel. The electron beam emitted by the electron gun is deflected once by the first pre-stage XY deflector, and the electromagnetic lens focuses the electron beam after the first deflection. The second pre-stage XY deflector then deflects the focused electron beam a second time, so that the electron beam is incident on the sample to be tested in the sample chamber with a predetermined beam size, convergence state, and spatial position, and is scattered with the sample to form a scattered electron beam group.

[0026] Step 5 specifically involves the electron imaging component magnifying and imaging a portion of the scattered electron beam group, projecting the magnified electron image onto a second fluorescent screen, exciting the second fluorescent screen to form a small-angle diffraction light signal, and the second detector detecting the small-angle diffraction light signal to obtain a small-angle electron diffraction image of the sample under test, thus completing small-angle and wide-angle electron diffraction.

[0027] A small-angle and wide-angle electron diffraction device, characterized by:

[0028] It includes an electron beam transmission channel, an electron beam generation unit arranged sequentially along the electron beam transmission channel from the incident end to the exit end, a sample chamber, a post-stage diffraction beam XY deflector, a first detection component, and a second detection component.

[0029] The electron beam generating unit includes an electron gun vacuum chamber connected to the incident end of the electron beam transmission channel and an electron gun disposed within the electron gun vacuum chamber; the electron gun is used to emit an electron beam into the electron beam transmission channel.

[0030] The sample chamber is used to place the sample to be tested, and the electron beam forms a scattered electron beam group after passing through the sample to be tested; the scattered electron beam group includes a transmitted electron beam and a diffracted electron beam.

[0031] The subsequent XY deflector of the diffraction beam is used to deflect the scattered electron beam three times.

[0032] The first detection component includes a first chamber connected to the electron beam transmission channel, a first fluorescent screen and a reflector sequentially arranged inside the first chamber along the emission direction of the scattered electron beam group, and a first detector arranged outside the first chamber. The first fluorescent screen has a first transmission aperture in the middle for releasing a portion of the scattered electron beam group from the first transmission aperture, which is then excited by another portion of the scattered electron beam group to form a wide-angle diffraction light signal. The reflector is arranged at an angle of 30° to 60° with the first fluorescent screen, and has a second transmission aperture in the middle corresponding to the first transmission aperture for continuing to release the portion of the scattered electron beam group from the second transmission aperture and reflecting the wide-angle diffraction light signal. The first detector is arranged in the optical path where the reflected wide-angle diffraction light signal is located to detect the wide-angle diffraction light signal and acquire a wide-angle electron diffraction image.

[0033] The second detection component includes a second chamber connected to the exit end of the electron beam transmission channel, a second fluorescent screen disposed inside the second chamber, and a second detector disposed outside the second chamber; the second fluorescent screen is capable of forming a local diffraction light signal under the excitation of the partial scattered electron beam group; the second detector is used to detect the local diffraction light signal to obtain a local electron diffraction image.

[0034] The electron gun vacuum chamber and the sample chamber are respectively connected to vacuum pumping equipment.

[0035] Furthermore, it also includes a first pre-stage XY deflector, an electromagnetic lens, and a second pre-stage XY deflector; the first pre-stage XY deflector, the electromagnetic lens, and the second pre-stage XY deflector are sequentially arranged in the electron beam transmission channel between the electron gun vacuum chamber and the sample chamber along the electron beam emission direction; the first pre-stage XY deflector is used to deflect the electron beam emitted by the electron gun once; the electromagnetic lens is used to focus the electron beam after the first deflection; and the second pre-stage XY deflector is used to deflect the focused electron beam a second time.

[0036] Furthermore, it also includes a vacuum differential valve and an electron imaging assembly; the vacuum differential valve is disposed on the electron beam transmission channel between the first pre-stage XY deflector and the electromagnetic lens, and is used to isolate or connect the electron gun vacuum chamber and the sample chamber; the electron imaging assembly is installed on the electron beam transmission channel between the first chamber and the second chamber, and is used to magnify and image the received portion of the scattered electron beam group.

[0037] A small-angle and wide-angle electron diffraction method, employing the aforementioned small-angle and wide-angle electron diffraction apparatus, is characterized by comprising the following steps:

[0038] Step 1: Place the sample to be tested in the sample chamber.

[0039] Step 2: Evacuate the electron gun vacuum chamber and the sample chamber separately using a vacuum pump to reduce the pressure in the electron gun vacuum chamber to less than [a certain value]. The pressure inside the sample chamber is less than And maintain the differential air extraction state between the two chambers.

[0040] Step 3: An electron beam is emitted into the electron beam transmission channel through an electron gun. The electron beam enters the sample chamber and is scattered with the sample to be tested, forming a scattered electron beam group; the scattered electron beam group includes a transmitted electron beam and a diffracted electron beam.

[0041] Step 4: The first fluorescent screen allows a portion of the scattered electron beam to pass through the first transmission aperture, and under the excitation of another portion of the scattered electron beam, a wide-angle diffraction light signal is formed. The mirror continues to allow the portion of the scattered electron beam to pass through the second transmission aperture in its middle, and reflects the wide-angle diffraction light signal to the first detector. The first detector detects the wide-angle diffraction light signal to obtain a wide-angle electron diffraction image of the sample to be tested.

[0042] Step 5: The second fluorescent screen generates a local diffraction light signal under the excitation of a portion of the scattered electron beam group. The second detector detects the local diffraction light signal to obtain the local electron diffraction image of the sample under test, thus completing small-angle and wide-angle electron diffraction.

[0043] Further, step 2 specifically involves closing the vacuum differential valve to isolate the electron gun vacuum chamber and the sample chamber from each other, and then using a vacuum pump to evacuate both the electron gun vacuum chamber and the sample chamber separately, so that the pressure inside the electron gun vacuum chamber is less than [a certain value]. The pressure inside the sample chamber is less than Once both chambers meet the predetermined vacuum conditions, the vacuum differential valve is opened to connect the electron gun vacuum chamber with the sample chamber, and the differential pumping state between the two chambers is maintained.

[0044] Step 3 specifically involves the electron gun emitting an electron beam into the electron beam transmission channel. The electron beam emitted by the electron gun is deflected once by the first pre-stage XY deflector, and the electromagnetic lens focuses the electron beam after the first deflection. The second pre-stage XY deflector then deflects the focused electron beam a second time, so that the electron beam is incident on the sample to be tested in the sample chamber with a predetermined beam size, convergence state, and spatial position, and is scattered with the sample to form a scattered electron beam group.

[0045] Step 4 specifically involves adjusting the XY deflector of the subsequent diffraction beam so that the scattered electron beam group is incident on the first fluorescent screen at a preset angle. The first fluorescent screen releases a portion of the scattered electron beam group through the first transmission aperture, and under the excitation of the other portion of the scattered electron beam group, it forms a wide-angle diffraction light signal. The reflector continues to release the portion of the scattered electron beam group through the second transmission aperture in its middle, and reflects the wide-angle diffraction light signal to the first detector. The first detector detects the reflected wide-angle diffraction light signal to obtain a wide-angle electron diffraction image of the sample under test.

[0046] Step 5 specifically involves the electron imaging component magnifying and imaging a portion of the scattered electron beam group, projecting the magnified electron image onto a second fluorescent screen, exciting the second fluorescent screen to form a local diffraction light signal, and the second detector detecting the local diffraction light signal to obtain a local electron diffraction image of the sample under test, thus completing small-angle and wide-angle electron diffraction.

[0047] The beneficial effects of this invention are:

[0048] 1. The present invention provides a small-angle and wide-angle electron diffraction device and method. By setting a first detection component and a second detection component in the same device, it is possible to detect the overall wide-angle diffraction region and the small-angle diffraction region near the transmitted electron beam, respectively. Thus, it can effectively avoid the interference of strong transmitted electron beam on weak small-angle diffraction signals and diffuse scattering signals in the central region, improve the resolution and utilization efficiency of small-angle diffraction signals, and facilitate the acquisition of structural information such as long-period structures, mesoscale ordered or disordered features, and interface distribution.

[0049] 2. This invention provides a small-angle and wide-angle electron diffraction apparatus and method. By setting a first detector component and a second detector component in the same apparatus, it is possible to simultaneously detect the overall wide-angle diffraction region and the small-angle diffraction region near the transmitted electron beam under the same time delay conditions, and synchronously obtain wide-angle electron diffraction images and small-angle electron diffraction images. This method avoids the problems of frequently changing the camera length, adjusting the detection parameters, or reconfiguring the detection optical path required in traditional apparatuses, thereby simplifying experimental operations and improving the accuracy of synchronous correlation analysis between diffraction data at different scales.

[0050] 3. The present invention provides a small-angle and wide-angle electron diffraction device and method. By setting a post-stage diffraction beam XY deflector and combining it with the first transmission aperture on the first fluorescent screen in the first detection component and the electron imaging component, it can accurately select, extract and detect the selected local diffraction electron beam at high magnification, thereby realizing the effective separation and enhancement of the target local diffraction information, and improving the ability to resolve structural dynamic details such as local structural distortion, defect evolution, phase separation and specific diffraction spot response.

[0051] 4. The small-angle and wide-angle electron diffraction apparatus and method provided by the present invention, under the condition that the positions of the detectors (i.e., the first detector and the second detector) remain basically unchanged, can achieve flexible switching between wide-angle diffraction overall detection, small-angle diffraction amplification detection, and selected local diffraction region detection by adjusting the working parameters of the XY deflector of the subsequent diffraction beam and the electron imaging component. As a result, the adaptability of the apparatus to different diffraction detection requirements and experimental efficiency can be improved, geometric errors caused by mechanical movement or optical path reconstruction can be reduced, and it is beneficial to carry out continuous, stable and correlated characterization of multi-scale diffraction information. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the structure of a small-angle and wide-angle electron diffraction device according to a first embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of a first embodiment of a small-angle and wide-angle electron diffraction device of the present invention;

[0054] Figure 3This is a schematic diagram of the electron imaging component, the second fluorescent screen, and the corresponding electron beam path in Embodiment 1 of the present invention;

[0055] Figure 4 This is the light spot pattern on the first fluorescent screen in Embodiment 1 of the present invention;

[0056] Figure 5 This is the light spot pattern on the second fluorescent screen in Embodiment 1 of the present invention;

[0057] Figure 6 A schematic diagram of the structure of a small-angle and wide-angle electron diffraction device according to a second embodiment of the present invention;

[0058] Figure 7 This is a schematic diagram of a second embodiment of a small-angle and wide-angle electron diffraction device of the present invention;

[0059] Figure 8 This is the light spot pattern on the first fluorescent screen in Embodiment 2 of the present invention;

[0060] Figure 9 This is the light spot pattern on the second fluorescent screen in Embodiment 2 of the present invention.

[0061] The attached figures are labeled as follows:

[0062] 1. Electron beam transmission channel; 2. Electron beam generation unit; 21. Electron gun vacuum chamber; 22. Electron gun; 3. Sample chamber; 4. First detection assembly; 41. First chamber; 42. First fluorescent screen; 421. First transmission aperture; 422. Zero-order Laue band diffraction spot; 43. Reflector; 431. Second transmission aperture; 44. First detector; 5. Second detection assembly; 51. Second chamber; 52. Second fluorescent screen; 521. Transmission beam spot; 522. Small-angle diffraction spot; 523. Local diffraction spot; 53. Second detector; 6. Sample to be tested; 7. First pre-stage XY deflector; 8. Electromagnetic lens; 9. Second pre-stage XY deflector; 10. Vacuum differential valve; 11. Post-stage diffraction beam XY deflector; 12. Electron imaging assembly; 121. Objective lens; 122. Intermediate mirror; 123. Projector lens. Detailed Implementation

[0063] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0064] Example 1:

[0065] Embodiment 1 of the present invention provides a small-angle and wide-angle electron diffraction device, combined with Figure 1and Figure 2 As shown, the electron diffraction device specifically includes an electron beam transmission channel 1, an electron beam generating unit 2 arranged sequentially along the electron beam transmission channel 1 from the incident end to the exit end, a first pre-stage XY deflector 7, a vacuum differential valve 10, an electromagnetic lens 8, a second pre-stage XY deflector 9, a sample chamber 3, a first detection component 4, an electron imaging component 12, and a second detection component 5.

[0066] The electron beam generating unit 2 includes an electron gun vacuum chamber 21 connected to the incident end of the electron beam transmission channel 1 and an electron gun 22 disposed in the electron gun vacuum chamber 21. In this embodiment, the electron gun 22 is a DC high-voltage electron gun, which is used to emit an ultrashort pulse electron beam into the electron beam transmission channel 1. The electron beam passes through the sample to be tested 6 and can be scattered with the sample to be tested 6 to form a scattered electron beam group, which includes a transmitted electron beam and a diffracted electron beam.

[0067] In other embodiments, the electron gun 22 is not limited to a DC high-voltage electron gun, but can also be a radio frequency electron gun or other electron sources capable of generating ultrashort electron pulses; the electron accelerating voltage can be optimized in the low-energy or high-energy region according to experimental requirements.

[0068] The first pre-stage XY deflector 7 is used to deflect the electron beam emitted by the electron gun 22 once, so as to fine-tune the trajectory of the electron beam before it enters the electromagnetic lens 8.

[0069] The vacuum differential valve 10 can isolate or connect the electron gun vacuum chamber 21 and the sample chamber 3 in a timely manner, so as to realize differential pumping and vacuum isolation between the electron gun vacuum chamber 21 and the sample chamber 3, which facilitates segmented vacuuming and maintenance.

[0070] The electromagnetic lens 8 is used to focus the electron beam after one deflection to improve the beam spot quality during the transmission process and to make the electron beam incident on the sample 6 under test with a predetermined beam spot size and convergence angle.

[0071] The second pre-stage XY deflector 9 is used to deflect the focused electron beam a second time, that is, to fine-tune the trajectory of the focused electron beam so that the electron beam has the required spatial position when it reaches the sample 6 to be tested.

[0072] Sample chamber 3 is used to place sample 6 to be tested; pump laser incident window is also provided on the side wall of sample chamber 3 for pump detection experiment.

[0073] The first detection component 4 is used to record wide-angle diffraction information such as zero-order Laue bands and higher-order Laue bands. The first detection component 4 includes a first chamber 41 connected to the electron beam transmission channel 1, a first fluorescent screen 42 and a reflector 43 arranged sequentially in the first chamber 41 along the emission direction of the scattered electron beam group, and a first detector 44 arranged outside the first chamber 41; the first fluorescent screen 42 has a first transmission hole 421 in the middle, which is used to release a part of the scattered electron beam group (this part of the scattered electron beam group may include a transmitted electron beam and a part of the diffracted electron beam, or it may only contain a part of the diffracted electron beam, and the angle between the released part of the diffracted electron beam and its electron beam axis is small) and is scattered by another part of the scattered electron beam group (this other part of the scattered electron beam group) The radio electron beam may consist of only one part of the diffracted electron beam, or it may consist of a transmitted electron beam and another part of the diffracted electron beam (the other part of the diffracted electron beam has a large angle between its axis and the electron beam axis) to excite and form a wide-angle diffracted light signal; the reflector 43 is set at an angle of 30° to 60° with the first fluorescent screen 42 (preferably 45° in this embodiment), and its middle part is provided with a second transmission hole 431 corresponding to the first transmission hole 421, for continuing to let the part of the scattered electron beam group through the second transmission hole 431 and reflecting the wide-angle diffracted light signal; the first detector 44 is set in the optical path where the wide-angle diffracted light signal is located to detect the wide-angle diffracted light signal and acquire a wide-angle electron diffraction image.

[0074] The electronic imaging component 12 is preferably an electromagnetic lens assembly structure. The electronic imaging component 12 is used to magnify and image the received portion of the scattered electron beam, such as... Figure 3 As shown, the electron imaging assembly 12 includes an objective lens 121, an intermediate lens 122, and a projection lens 123 arranged sequentially along the transmission direction of the scattered electron beam. By adjusting the excitation current of the objective lens 121, the intermediate lens 122, and the projection lens 123, the equivalent focal length of each lens is changed, so that the image plane of the magnified scattered electron beam coincides with the plane of the second fluorescent screen 52, thereby obtaining small-angle diffraction or local diffraction detail information at different magnifications.

[0075] Its working principle is as follows: A portion of the scattered electron beam to be magnified first enters the objective lens 121, forming an intermediate image behind the objective lens 121; the intermediate mirror 122 further magnifies the intermediate image and transmits it to the projection mirror 123; the projection mirror 123 projects the magnified intermediate image onto the second fluorescent screen 52 to form a small-angle diffraction light signal, which is then detected by the second detector 53. By adjusting the excitation currents of the objective lens 121, the intermediate mirror 122, and the projection mirror 123 respectively, the imaging magnification can be continuously adjusted while keeping the imaging plane basically unchanged, so as to adapt to the measurement requirements of different scattering angle ranges and spatial resolutions.

[0076] The first pre-stage XY deflector 7 and the second pre-stage XY deflector 9 can be electrostatic deflection plates, electromagnetic scanning coils, or other combinations; the number and arrangement of the electromagnetic lens 8 and the objective lens 121, intermediate lens 122 and projection lens 123 of the electronic imaging assembly 12 can also be increased, decreased or recombined according to the required magnification, field of view and device length to form a single-stage or multi-stage electromagnetic lens system.

[0077] The second detection component 5 includes a second chamber 51 connected to the exit end of the electron beam transmission channel 1, a second fluorescent screen 52 disposed in the second chamber 51, and a second detector 53 disposed outside the second chamber 51; the second fluorescent screen 52 can form a small-angle diffraction light signal under the excitation of the partial scattered electron beam group; the second detector 53 is used to detect the small-angle diffraction light signal to obtain a small-angle electron diffraction image.

[0078] In this first embodiment, both the first detector 44 and the second detector 53 are EMCCD cameras. In other embodiments, the first fluorescent screen 42 and the second fluorescent screen 52 in the first detector assembly 4 and the second detector assembly 5 can be replaced with other types of imaging screens, or they can be integrated with a direct electron detector, image intensifier, or high-speed camera; the shape and size of the first transmission aperture 421 and the second transmission aperture 431 can be adjusted according to the required transmission and small-angle scattering angle range, or a multi-hole or adjustable aperture structure can be adopted to adapt to different experimental conditions.

[0079] The electron gun vacuum chamber 21 and the sample chamber 3 are respectively connected to vacuum pumping equipment, which in this embodiment is a mechanical pump, molecular pump, or ion pump. Vacuum pump connection flanges are provided at the bottom of the electron gun vacuum chamber 21 and the sample chamber 3. The vacuum pump can provide a stable high vacuum environment for electron beam transmission and diffraction measurement.

[0080] In this embodiment, a control and synchronization system is also provided. The control and synchronization system includes functional modules such as power control, timing synchronization, and data acquisition and storage, which are used to coordinate and control the working states of the pump laser, electron gun 22, first detector 44, and second detector 53. By adjusting the time delay between the pulsed electron beam and the pump laser, corresponding wide-angle diffraction, small-angle diffraction, and local diffraction magnification patterns can be stably acquired under different time delay conditions.

[0081] The acquisition of small-angle and wide-angle electron diffraction images using the aforementioned small-angle and wide-angle electron diffraction devices specifically includes the following steps:

[0082] Step 1: Place the sample to be tested 6 on the sample holder inside the sample chamber 3.

[0083] Step 2: Close the vacuum differential valve 10 to isolate the electron gun vacuum chamber 21 and the sample chamber 3 from each other; then, use a vacuum pump to evacuate both the electron gun vacuum chamber 21 and the sample chamber 3, so that the pressure inside the electron gun vacuum chamber 21 is less than [a certain value]. The pressure inside sample chamber 3 is less than Once both chambers meet the predetermined vacuum conditions, the vacuum differential valve 10 is opened to connect the electron gun vacuum chamber 21 with the sample chamber 3, and to maintain the differential pumping state between the two chambers.

[0084] Step 3: Set the time delay between the pump laser and the probe pulse electron beam. The electron beam is emitted into the electron beam transmission channel 1 via the electron gun 22. The first pre-stage XY deflector 7, the electromagnetic lens 8, and the second pre-stage XY deflector 9 work together to coordinate the adjustment of the electron beam. Specifically, the first pre-stage XY deflector 7 performs a primary deflection of the electron beam, adjusting its propagation trajectory before entering the electromagnetic lens 8. The electromagnetic lens 8 focuses the electron beam after the primary deflection. The second pre-stage XY deflector 9 performs a secondary deflection of the focused electron beam, finely adjusting its propagation trajectory. This ensures that the electron beam, with a predetermined beam size, convergence state, and spatial position, enters the sample chamber 3 and is scattered by the sample 6, forming a scattered electron beam group. This scattered electron beam group includes a transmitted electron beam and a diffracted electron beam.

[0085] Step 4: After being scattered by the sample 6, the first fluorescent screen 42 transmits the transmitted electron beam propagating near the electron beam axis and a portion of the diffracted electron beam with a small angle to the electron beam axis through the first transmission aperture 421. Under the excitation of another portion of the diffracted electron beam with a larger angle to the electron beam axis, a wide-angle diffracted light signal is formed. The reflecting mirror 43 continues to transmit the transmitted electron beam and a portion of the diffracted electron beam emitted by the first fluorescent screen 42 through the second transmission aperture 431 in its middle, and reflects the wide-angle diffracted light signal to the first detector 44. The first detector 44 detects the wide-angle diffracted light signal to obtain the wide-angle electron diffraction image of the sample 6. Figure 4 As shown, a zero-order Laue band diffraction spot 422 is formed on the first fluorescent screen 42 at this time; under the premise that a high-order Laue band wide-angle diffraction signal can be generated, and when the detection geometry meets the requirements, a high-order Laue band diffraction light signal can be formed on the first fluorescent screen 42.

[0086] Step 5: The electron imaging component 12 magnifies and images the transmitted electron beam and a portion of the diffracted electron beam emitted by the reflector 43, and projects the magnified electron image onto the second fluorescent screen 52, exciting the second fluorescent screen 52 to emit light and form a small-angle diffraction light signal, such as... Figure 5As shown, at this time, a transmission beam spot 521 located in the middle and a small-angle diffraction spot 522 located around the transmission beam spot 521 will be formed on the second fluorescent screen 52; then the second detector 53 will detect the small-angle diffraction light signal to obtain the small-angle electron diffraction image of the sample 6 to be tested, thus completing the small-angle and wide-angle electron diffraction.

[0087] Thus, the first detector 44 obtains the wide-angle electron diffraction image of the sample 6 to be tested, and the second detector 53 obtains the small-angle electron diffraction image of the sample 6 to be tested, thereby simultaneously obtaining the wide-angle electron diffraction image and the small-angle electron diffraction image near the transmitted electron beam of the sample 6 to be tested under the same device and the same time delay.

[0088] Example 2:

[0089] The small-angle and wide-angle electron diffraction device provided in this embodiment is basically the same in structure as that in embodiment one, such as... Figure 6 and Figure 7 As shown, the difference is that it also includes a post-stage diffraction beam XY deflector 11.

[0090] The post-stage diffraction beam XY deflector 11 is disposed on the electron beam transmission channel 1 between the sample chamber 3 and the first chamber 41. Preferably, it consists of two or more sets of orthogonally arranged electrostatic deflection plates or electromagnetic deflection coils. It is used to apply an adjustable transverse deflection field to the scattered electron beam group after it has been scattered by the sample 6, thereby controlling the offset of the scattered electron beam group on the first fluorescent screen 42. By adjusting the deflection potential or deflection current, the selected local diffraction electron beam can be precisely guided to the first transmission aperture 421.

[0091] In use, only steps 4 and 5 differ from step 4 in Example 1;

[0092] Step 4 specifically involves adjusting the XY deflector 11 of the subsequent diffraction beam so that the scattered electron beam group is incident on the first fluorescent screen 42 at a preset angle. At this time, the first fluorescent screen 42 only allows a portion of the diffracted electron beam from the scattered electron beam group to pass through the first transmission aperture 421, and forms a wide-angle diffraction light signal under the excitation of the transmitted electron beam and another portion of the diffracted electron beam. The reflector 43 continues to allow the portion of the diffracted electron beam allowed by the first fluorescent screen 42 to pass through, and reflects the wide-angle diffraction light signal to the first detector 44. The first detector 44 detects the wide-angle diffraction light signal to obtain the wide-angle electron diffraction image of the sample 6 to be tested.

[0093] Step 5 specifically involves the electron imaging component 12 magnifying and imaging a portion of the diffracted electron beam released by the reflector 43, and projecting the magnified electron image onto the second fluorescent screen 52, thereby exciting the second fluorescent screen 52 to form a local diffraction light signal. The second detector 53 then detects the local diffraction light signal to obtain a local electron diffraction image of the sample 6 under test, thus completing the detection of wide-angle diffraction and selected local diffraction information.

[0094] Combination Figure 4 , Figure 8 and Figure 9 As shown, zero-order Laue band diffraction spots 422 are distributed around the first transmission aperture 421 on the first fluorescent screen 42, among which the diffraction spots marked in blue are the local diffraction spots 523 to be magnified. After adjusting the XY deflector 11 of the subsequent diffraction beam to deflect the scattered electron beam group, the local diffraction spot 523 can be deflected to the first transmission aperture 421 on the first fluorescent screen 42, and let it enter the electron imaging component 12 for magnification and imaging. Then the corresponding magnified result can be obtained on the second fluorescent screen 52. The area shown in the blue circle is the local diffraction spot 523 magnified by the electron imaging component 12.

[0095] Thus, with the same device and the same time delay, wide-angle electron diffraction images and magnified local electron diffraction images can be acquired simultaneously.

[0096] In this invention, the small-angle and wide-angle electron diffraction modes and the local diffraction region detection mode can be combined, expanded or simplified according to actual applications. For example, only the small-angle diffraction amplification function can be retained, or other selected area diffraction can be further added. As long as the XY deflector of the subsequent diffraction beam and the electron imaging component are used in the same device to achieve selective extraction and amplification detection of multiple diffraction regions.

[0097] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A small-angle and wide-angle electron diffraction device, characterized in that: It includes an electron beam transmission channel (1), an electron beam generation unit (2) arranged sequentially from the incident end to the exit end on the electron beam transmission channel (1), a sample chamber (3) for placing the sample to be tested (6), and a first detection component (4) and a second detection component (5). The electron beam generating unit (2) includes an electron gun vacuum chamber (21) connected to the incident end of the electron beam transmission channel (1) and an electron gun (22) disposed in the electron gun vacuum chamber (21); the electron gun (22) is used to emit an electron beam into the electron beam transmission channel (1), and the electron beam forms a scattered electron beam group after passing through the sample to be tested (6); the scattered electron beam group includes a transmitted electron beam and a diffracted electron beam; The first detection component (4) includes a first chamber (41) connected to the electron beam transmission channel (1), a first fluorescent screen (42) and a reflector (43) arranged sequentially in the first chamber (41) along the emission direction of the scattered electron beam group, and a first detector (44) arranged outside the first chamber (41); the first fluorescent screen (42) is provided with a first transmission hole (421) in the middle, which is used to release a part of the scattered electron beam group from the first transmission hole (421) and be excited by another part of the scattered electron beam group to form a wide-angle diffraction light signal; the reflector (43) is arranged at an angle of 30°~60° with the first fluorescent screen (42), and is provided with a second transmission hole (431) in the middle corresponding to the first transmission hole (421), which is used to continue to release the part of the scattered electron beam group from the second transmission hole (431) and reflect the wide-angle diffraction light signal; the first detector (44) is arranged in the optical path where the reflected wide-angle diffraction light signal is located, so as to detect the wide-angle diffraction light signal and obtain a wide-angle electron diffraction image; The second detection component (5) includes a second chamber (51) connected to the exit end of the electron beam transmission channel (1), a second fluorescent screen (52) disposed in the second chamber (51), and a second detector (53) disposed outside the second chamber (51); the second fluorescent screen (52) is capable of forming a small-angle diffraction light signal under the excitation of the part of the scattered electron beam group; the second detector (53) is used to detect the small-angle diffraction light signal to obtain a small-angle electron diffraction image; The electron gun vacuum chamber (21) and the sample chamber (3) are respectively connected to vacuum pumping equipment.

2. The small-angle and wide-angle electron diffraction apparatus according to claim 1, characterized in that: It also includes a first pre-stage XY deflector (7), an electromagnetic lens (8), and a second pre-stage XY deflector (9); The first pre-stage XY deflector (7), the electromagnetic lens (8), and the second pre-stage XY deflector (9) are sequentially arranged on the electron beam transmission channel (1) between the electron gun vacuum chamber (21) and the sample chamber (3) along the electron beam emission direction; The first pre-stage XY deflector (7) is used to deflect the electron beam emitted by the electron gun (22) once; The electromagnetic lens (8) is used to focus the electron beam after one deflection; The second pre-stage XY deflector (9) is used to deflect the focused electron beam a second time.

3. The small-angle and wide-angle electron diffraction apparatus according to claim 2, characterized in that: It also includes a vacuum differential valve (10) and an electronic imaging assembly (12); The vacuum differential valve (10) is located on the electron beam transmission channel (1) between the first pre-stage XY deflector (7) and the electromagnetic lens (8) to isolate or connect the electron gun vacuum chamber (21) and the sample chamber (3). The electron imaging component (12) is installed on the electron beam transmission channel (1) between the first chamber (41) and the second chamber (51) for magnifying and imaging the received portion of the scattered electron beam group.

4. A small-angle and wide-angle electron diffraction method, employing the small-angle and wide-angle electron diffraction apparatus according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Place the sample to be tested (6) in the sample chamber (3); Step 2: Vacuum the electron gun vacuum chamber (21) and the sample chamber (3) using a vacuum pump to make the pressure inside the electron gun vacuum chamber (21) less than 100°C. The pressure inside the sample chamber (3) is less than And maintain the differential pumping state between the two chambers; Step 3: An electron beam is emitted into the electron beam transmission channel (1) through the electron gun (22). The electron beam enters the sample chamber (3) and is scattered with the sample to be tested (6) to form a scattered electron beam group; the scattered electron beam group includes a transmitted electron beam and a diffracted electron beam. Step 4: The first fluorescent screen (42) releases a portion of the scattered electron beam group through the first transmission hole (421) and forms a wide-angle diffraction light signal under the excitation of another portion of the scattered electron beam group. The mirror (43) continues to release the portion of the scattered electron beam group through the second transmission hole (431) in its middle and reflects the wide-angle diffraction light signal to the first detector (44). The first detector (44) detects the reflected wide-angle diffraction light signal to obtain the wide-angle electron diffraction image of the sample (6) to be tested. Step 5: The second fluorescent screen (52) generates a small-angle diffraction light signal under the excitation of a portion of the scattered electron beam group. The second detector (53) detects the small-angle diffraction light signal to obtain the small-angle electron diffraction image of the sample to be tested (6), thus completing the small-angle and wide-angle electron diffraction.

5. The small-angle and wide-angle electron diffraction method according to claim 4, characterized in that: Step 2 specifically involves closing the vacuum differential valve (10) to isolate the electron gun vacuum chamber (21) and the sample chamber (3) from each other, and then using a vacuum pump to evacuate both the electron gun vacuum chamber (21) and the sample chamber (3) to reduce the pressure inside the electron gun vacuum chamber (21) to less than 100°C. The pressure inside the sample chamber (3) is less than After both chambers meet the predetermined vacuum conditions, the vacuum differential valve (10) is opened to connect the electron gun vacuum chamber (21) with the sample chamber (3) and maintain the differential pumping state between the two chambers. Step 3 specifically involves the electron gun (22) emitting an electron beam into the electron beam transmission channel (1), the electron beam emitted by the electron gun (22) being deflected once by the first pre-stage XY deflector (7), the electromagnetic lens (8) focusing the electron beam after the first deflection, and the second pre-stage XY deflector (9) deflecting the focused electron beam a second time, so that the electron beam is incident on the sample to be tested (6) in the sample chamber (3) with a predetermined beam size, convergence state and spatial position, and scatters with the sample to be tested (6) to form a scattered electron beam group; Step 5 specifically involves the electron imaging component (12) magnifying and imaging a portion of the scattered electron beam group, and projecting the magnified electron image onto the second fluorescent screen (52), exciting the second fluorescent screen (52) to form a small-angle diffraction light signal, and the second detector (53) detecting the small-angle diffraction light signal to obtain the small-angle electron diffraction image of the sample to be tested (6), thus completing small-angle and wide-angle electron diffraction.

6. A small-angle and wide-angle electron diffraction device, characterized in that: It includes an electron beam transmission channel (1), an electron beam generation unit (2) arranged sequentially along the electron beam transmission channel (1) from the incident end to the exit end, a sample chamber (3), a post-stage diffraction beam XY deflector (11), a first detection component (4), and a second detection component (5). The electron beam generating unit (2) includes an electron gun vacuum chamber (21) connected to the incident end of the electron beam transmission channel (1) and an electron gun (22) disposed in the electron gun vacuum chamber (21); the electron gun (22) is used to emit an electron beam into the electron beam transmission channel (1); The sample chamber (3) is used to place the sample to be tested (6), and the electron beam forms a scattered electron beam group after passing through the sample to be tested (6); the scattered electron beam group includes a transmitted electron beam and a diffracted electron beam. The post-stage diffraction beam XY deflector (11) is used to deflect the scattered electron beam group three times; The first detection component (4) includes a first chamber (41) connected to the electron beam transmission channel (1), a first fluorescent screen (42) and a reflector (43) arranged sequentially in the first chamber (41) along the emission direction of the scattered electron beam group, and a first detector (44) arranged outside the first chamber (41); the first fluorescent screen (42) is provided with a first transmission hole (421) in the middle, which is used to release a part of the scattered electron beam group from the first transmission hole (421) and be excited by another part of the scattered electron beam group to form a wide-angle diffraction light signal; the reflector (43) is arranged at an angle of 30°~60° with the first fluorescent screen (42), and is provided with a second transmission hole (431) in the middle corresponding to the first transmission hole (421), which is used to continue to release the part of the scattered electron beam group from the second transmission hole (431) and reflect the wide-angle diffraction light signal; the first detector (44) is arranged in the optical path where the reflected wide-angle diffraction light signal is located, so as to detect the wide-angle diffraction light signal and obtain a wide-angle electron diffraction image; The second detection component (5) includes a second chamber (51) connected to the exit end of the electron beam transmission channel (1), a second fluorescent screen (52) disposed in the second chamber (51), and a second detector (53) disposed outside the second chamber (51); the second fluorescent screen (52) is capable of forming a local diffraction light signal under the excitation of the partial scattered electron beam group; the second detector (53) is used to detect the local diffraction light signal to obtain a local electron diffraction image; The electron gun vacuum chamber (21) and the sample chamber (3) are respectively connected to vacuum pumping equipment.

7. The small-angle and wide-angle electron diffraction apparatus according to claim 6, characterized in that: It also includes a first pre-stage XY deflector (7), an electromagnetic lens (8), and a second pre-stage XY deflector (9); The first pre-stage XY deflector (7), the electromagnetic lens (8), and the second pre-stage XY deflector (9) are sequentially arranged on the electron beam transmission channel (1) between the electron gun vacuum chamber (21) and the sample chamber (3) along the electron beam emission direction; The first pre-stage XY deflector (7) is used to deflect the electron beam emitted by the electron gun (22) once; The electromagnetic lens (8) is used to focus the electron beam after one deflection; The second pre-stage XY deflector (9) is used to deflect the focused electron beam a second time.

8. The small-angle and wide-angle electron diffraction apparatus according to claim 7, characterized in that: It also includes a vacuum differential valve (10) and an electronic imaging assembly (12); The vacuum differential valve (10) is located on the electron beam transmission channel (1) between the first pre-stage XY deflector (7) and the electromagnetic lens (8) to isolate or connect the electron gun vacuum chamber (21) and the sample chamber (3). The electron imaging component (12) is installed on the electron beam transmission channel (1) between the first chamber (41) and the second chamber (51) for magnifying and imaging the received portion of the scattered electron beam group.

9. A small-angle and wide-angle electron diffraction method, employing the small-angle and wide-angle electron diffraction apparatus according to any one of claims 6-8, characterized in that, Includes the following steps: Step 1: Place the sample to be tested (6) in the sample chamber (3); Step 2: Vacuum the electron gun vacuum chamber (21) and the sample chamber (3) using a vacuum pump to make the pressure inside the electron gun vacuum chamber (21) less than 100°C. The pressure inside the sample chamber (3) is less than And maintain the differential pumping state between the two chambers; Step 3: An electron beam is emitted into the electron beam transmission channel (1) through the electron gun (22). The electron beam enters the sample chamber (3) and is scattered with the sample to be tested (6) to form a scattered electron beam group; the scattered electron beam group includes a transmitted electron beam and a diffracted electron beam. Step 4: The first fluorescent screen (42) releases a portion of the scattered electron beam group through the first transmission hole (421) and forms a wide-angle diffraction light signal under the excitation of another portion of the scattered electron beam group. The mirror (43) continues to release the portion of the scattered electron beam group through the second transmission hole (431) in its middle and reflects the wide-angle diffraction light signal to the first detector (44). The first detector (44) detects the wide-angle diffraction light signal and obtains the wide-angle electron diffraction image of the sample (6) to be tested. Step 5: The second fluorescent screen (52) generates a local diffraction light signal under the excitation of a portion of the scattered electron beam group. The second detector (53) detects the local diffraction light signal to obtain the local electron diffraction image of the sample (6) to be tested, thus completing small-angle and wide-angle electron diffraction.

10. The small-angle and wide-angle electron diffraction method according to claim 9, characterized in that: Step 2 specifically involves closing the vacuum differential valve (10) to isolate the electron gun vacuum chamber (21) and the sample chamber (3) from each other, and then using a vacuum pump to evacuate both the electron gun vacuum chamber (21) and the sample chamber (3) to reduce the pressure inside the electron gun vacuum chamber (21) to less than 100°C. The pressure inside the sample chamber (3) is less than After both chambers meet the predetermined vacuum conditions, the vacuum differential valve (10) is opened to connect the electron gun vacuum chamber (21) with the sample chamber (3) and maintain the differential pumping state between the two chambers. Step 3 specifically involves the electron gun (22) emitting an electron beam into the electron beam transmission channel (1), the electron beam emitted by the electron gun (22) being deflected once by the first pre-stage XY deflector (7), the electromagnetic lens (8) focusing the electron beam after the first deflection, and the second pre-stage XY deflector (9) deflecting the focused electron beam a second time, so that the electron beam is incident on the sample to be tested (6) in the sample chamber (3) with a predetermined beam size, convergence state and spatial position, and scatters with the sample to be tested (6) to form a scattered electron beam group; Step 4 specifically involves adjusting the XY deflector (11) of the subsequent diffraction beam so that the scattered electron beam group is incident on the first fluorescent screen (42) at a preset angle. The first fluorescent screen (42) releases a portion of the scattered electron beam group from the first transmission hole (421) and forms a wide-angle diffraction light signal under the excitation of another portion of the scattered electron beam group. The mirror (43) continues to release the portion of the scattered electron beam group through the second transmission hole (431) in its middle and reflects the wide-angle diffraction light signal to the first detector (44). The first detector (44) detects the reflected wide-angle diffraction light signal to obtain the wide-angle electron diffraction image of the sample (6) to be tested. Step 5 specifically involves the electron imaging component (12) magnifying and imaging a portion of the scattered electron beam group, and projecting the magnified electron image onto the second fluorescent screen (52), exciting the second fluorescent screen (52) to form a local diffraction light signal, and the second detector (53) detecting the local diffraction light signal to obtain a local electron diffraction image of the sample to be tested (6), thus completing small-angle and wide-angle electron diffraction.

Images